Ok lets discuss this then. Why the hell are people still paying out a crap load of money of GW primers and spray paints, GW are charging £9.50 for a can of primer, this is just stupid. Army painter are also charging about the same depending where you shop £8-10 range.
So lets work this out. You are going to start a new project, and you are picking up your supplies.
For the most part you are going to grab
Black Primer
White Primer
Clear coat
That's a total cost of £28.50.
Now lets look at the alternative.
Airbrush and compressor. £50 on Ebay
£2 for some Grey Primer
£2 for Matt finish Clear coat
£2 White Paint
£2 Black paint.
So that's a total cost of £58
Wow you save £29.50 if you go for GW sprays, Or do you.
Lets be honest here, a can of primer from GW will last you a couple of units and a few tanks, and then you have to go and spend £9.50 again to get some more. But if you go with an airbrush and compressor you have a high initial cost but the paints are stupidly cheap, and you can take it from me that those tiny little Madel Air pot by Vallejo out last a Citedel spray can, because you don't over spray the model and waste loads of paint. The paint is more directed at the model, rather that shooting out an arc of paint that decorates what ever you are spraying near.
Within 6 moths of using an airbrush and a compressor, you would of saved money on your hobby. your primer coats will be thinner and better. leaving more sharp detail edges on the model for an overall better look.
Its not even the fact that your saving money. I mean that is just on undercoating alone. How long does it take you to undercoat, And brush basecoat an entire squad of space marines? I bet its an hour or two at best.
I can undercoat, pre-shade, base coat, wash, and highlight a squad in half an hour, all with an airbrush.
The advantages are amazing, think of those tanks you are painting, watering down the paint, and applying countless thin layers to minimize those brush strokes. An airbrush saves you time and money full stop.
Now lets talk about GW answer to airbrushing. The cheapest of the cheap Hand flamer shaped Air brush.
They charge £20 for this and then £5.50 for a can of compressed air, by the time you have painted an army, you would of used about 6 cans of compressed air, its not a viable option when half decent compressors are so cheap now.
There is more of a bonus, if you use Model air paints you can do all your spraying in the comfort of your own home they are all water based acrylics that have no fumes what so ever, meaning your painting area does not stink of that typical GW spray paint smell.
Now don't get me wrong, an airbrush does not replace a brush and a pot of paint, you still need to do some hand brushing. But hand brushing the details on a model is fine, there are no large areas that brush strokes notice on.
Now let's talk about paints for the airbrush. You are not going to want to try and use GW paints, they are useless for airbrushing. You will waste so much paint trying to thin them properly that it will cost you money. The GW paints DO NOT thin properly at all. They are designed for hand brushing, and there pigments are not fine enough to be properly used with an airbrush. The only thing that has managed to get them going through an airbrush half decently is matt medium, With a couple of drops of air brush thinner. But this gives you the problems of inaccurate mixes that can lead to unwanted non unification of unit colors.
So i suggest Badjer paints or Vallejo model air. Now these go for around £2 each. And don't think to your self, "I have hundreds of GW paints, I don't want to start again". You don't need to. The only paints you need to buy are the main ones for undercoating, base coating, and clear coating. The rest can be done with your GW paints.
Save your self some money and some time, And go grab an airbrush. You will thank your self for it.
For an awesome tutorial and help and advice on everything airbrush related check out Chung's channel.